Plane Stress Tutorial[1]

7/29/2019 Plane Stress Tutorial[1]

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ME 455/555 Intro to Finite Element Analysis Winter 10 Abaqus/CAE Plane Stress tutorial

2010 Hormoz Zareh & Jayson Martinez 1 Portland State University, Mechanical Engineering

Abaqus Plane Stress Tutorial

Problem Description

The steel bracket is fixed to a wall along its left side. A tensile pressure force with a total magnitude of 5000 N is applied

to the right side of the bracket. The bracket contains one line of symmetry, so only half of the geometry is to be

modeled. Determine the stresses in the bracket.


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Analysis Steps1. Start Abaqus and choose to create a new model database2. In the model tree double click on the Parts node (or right click on parts and select Create)

3. In the Create Part dialog box (shown above) name the part and selecta. 2D Planarb. Deformablec. Shelld. Approximate size = 2

4. Create the geometry shown below (not discussed here)


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5. Double click on the Materials node in the model tree

a. Name the new material and give it a descriptionb. Click on the Mechanical tabElasticityElasticc. Define Youngs Modulus and the Poissons Ratio (use SI units)

i. WARNING: There are no predefined system of units within Abaqus, so the user is responsiblefor ensuring that the correct values are specified


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6. Double click on the Sections node in the model treea. Name the section PlaneStressProperties and select Solid for the category and Homogeneous for

the type

b. Select the material created above (Steel) and set the thickness to 0.01

7. Expand the Parts node in the model tree and double click on Section Assignmentsa. Select the surface geometry in the viewportb. Select the section created above (PlaneStressProperties)

8. Expand the Assembly node in the model tree and then double click on Instancesa. Select Dependent for the instance type

9. In the model tree, under the expanded Assembly node, double click on Sets


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a. Name the set Fixedb. Select the left edge of the surface in the viewport

c. Create another set named Symmetryd. Select the two lower horizontal edges of the surface in the viewport

10. In the model tree, under the expanded Assembly node, double click on Surfacesa. Name the surface PressureLoadb. Select the right edge of the surface in the viewport

11.Double click on the Steps node in the model treea. Name the step, set the procedure to General, and select Static, Generalb. Give the step a description


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12.Expand the Field Output Requests node in the model tree, and then double click on F-Output-1 (F-Output-1 wasautomatically generated when creating the step)

a. Uncheck the variables Strains and Contact

13.Expand the History Output Requests node in the model tree, and then right click on H-Output-1 (H-Output-1 wasautomatically generated when creating the step) and select Delete


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14.Double click on the BCs node in the model treea. Name the boundary conditioned Fixed and select Symmetry/Antisymmetry/Encastre for the type

b. In the prompt area click on the Sets buttonc. Select the set named Fixed

d. Select ENCASTRE for the boundary condition (means clampedBC).


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e. Repeat the procedure for the symmetry restraint using the set named Symmetry, select YSYMM forthe boundary condition

15.Double click on the Loads node in the model treea. Name the load Pressure and select Pressure as the type

b. Select surface named Pressurec. For the magnitude enter -5e6

i. Note that because we have been using standard SI units the load applied is -5x106 N/m2 which isa total of -2500 N distributed across the right edge of the surface

2500

(0.05)(0.01)


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16. In the model tree double click on Mesh for the Bracket part, and in the toolbox area click on the AssignElement Type icon

a. Select Standard for element typeb. Select Linear for geometric orderc. Select Plane Stress for familyd. Note that the name of the element (CPS4R) and its description are given below the element controls

17. In the toolbox area click on the Assign Mesh Controls icona. Change the element shape to Quad


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18. In the toolbox area click on the Seed Part icona. Set the approximate global size to 0.01

19. In the toolbox area click on the Mesh Part icon

20. In the model tree double click on the Job nodea. Name the job Bracketb. Give the job a description


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21. In the model tree right click on the job just created (Bracket) and select Submita. While Abaqus is solving the problem right click on the job submitted (Bracket), and select Monitor

b. In the Monitor window check that there are no errors or warningsi. If there are errors, investigate the cause(s) before resolvingii. If there are warnings, determine if the warnings are relevant, some warnings can be safely

ignored


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22. In the model tree right click on the submitted and successfully completed job (Bracket), and select Results

23. In the menu bar click on ViewportViewport Annotations Optionsa. Uncheck the Show compass optionb. The locations of viewport items can be specified on the corresponding tab in the Viewport Annotations

Options


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24.Display the deformed contour of the (Von) Mises stressa. In the toolbox area click on the Plot Contours on Deformed Shape icon

25.To determine the stress values, from the menu bar click ToolsQuerya. Check the boxes labeled Nodes and S, Misesb. In the viewport mouse over the element of interestc. Note that Abaqus reports stress values from the integration points, which may differ slightly from the

values determined by projecting values from surrounding integration points to the nodes

i. The minimum and maximum stress values contained in the legend are from the stressesprojected to the nodes

d. Click on an element to store it in the Selected Probe Values portion of the dialogue box


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26.To change the output being displayed, in the menu bar click on ResultsField Outputa. Select Spatial displacement at nodes

i. Invariant = Magnitude

27.To create a text file containing the stresses and reaction forces (including total), in the menu bar click onReportField Output

a. For the output variable select (Von) Misesb. On the Setup tab specify the name and the location for the text file


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c. Uncheck the Column totals optiond. Click Apply

a. Back on the Variable tab change the position to Unique Nodalb. Uncheck the stress variable, and select the RF1 reaction forcec. On the Setup tab, check the Column totals optiond. Click OK


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28.Open the .rpt file with any text editora. One thing to check is that the total reaction force is equal to the applied load (-2,500 N)

Documents

Plane Stress Tutorial[1]